diff --git a/scripts/bundle-a2ui.sh b/scripts/bundle-a2ui.sh
index a1cf7ff2b..304002324 100755
--- a/scripts/bundle-a2ui.sh
+++ b/scripts/bundle-a2ui.sh
@@ -10,12 +10,21 @@ trap on_error ERR
 ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 HASH_FILE="$ROOT_DIR/src/canvas-host/a2ui/.bundle.hash"
 OUTPUT_FILE="$ROOT_DIR/src/canvas-host/a2ui/a2ui.bundle.js"
+A2UI_RENDERER_DIR="$ROOT_DIR/vendor/a2ui/renderers/lit"
+A2UI_APP_DIR="$ROOT_DIR/apps/shared/ClawdbotKit/Tools/CanvasA2UI"
+
+# Docker builds exclude vendor/apps via .dockerignore.
+# In that environment we must keep the prebuilt bundle.
+if [[ ! -d "$A2UI_RENDERER_DIR" || ! -d "$A2UI_APP_DIR" ]]; then
+  echo "A2UI sources missing; keeping prebuilt bundle."
+  exit 0
+fi
 
 INPUT_PATHS=(
   "$ROOT_DIR/package.json"
   "$ROOT_DIR/pnpm-lock.yaml"
-  "$ROOT_DIR/vendor/a2ui/renderers/lit"
-  "$ROOT_DIR/apps/shared/ClawdbotKit/Tools/CanvasA2UI"
+  "$A2UI_RENDERER_DIR"
+  "$A2UI_APP_DIR"
 )
 
 collect_files() {
@@ -46,7 +55,7 @@ if [[ -f "$HASH_FILE" ]]; then
   fi
 fi
 
-pnpm -s exec tsc -p vendor/a2ui/renderers/lit/tsconfig.json
-rolldown -c apps/shared/ClawdbotKit/Tools/CanvasA2UI/rolldown.config.mjs
+pnpm -s exec tsc -p "$A2UI_RENDERER_DIR/tsconfig.json"
+rolldown -c "$A2UI_APP_DIR/rolldown.config.mjs"
 
 echo "$current_hash" > "$HASH_FILE"